title: Contamination profile of DDT and HCH in surface sediments and their spatial distribution from North-East India.
abstract: Contamination status and spatial distribution of DDTs and HCHs were investigated in sediments collected from ponds and riverine system from districts Nagaon and Dibrugarh, North East India. A total of 113 surface sediment samples were collected from both the districts including 43 from ponds/wetlands and 70 from rivers/streams. Based on dry weight (dw), the mean concentration of ∑HCH and ∑DDT in sediments were found to be 287 ng/g (71.2-834 ng/g) and 321 ng/g (30.1-918 ng/g) for district Dibrugarh while 330 ng/g (39.2-743 ng/g) and 378 ng/g (72.5-932 ng/g) for district Nagaon, respectively. DDTs and HCHs in sediments were well influenced by total organic carbon, clay and silt content of sediments. Source identification revealed that sediment residue levels have originated from long and recent mixed source of technical HCH and Lindane for HCHs and mainly technical DDT for DDTs. Majority of samples exceeded the sediment quality guidelines (SQG) for γ-HCH, p,p'-DDT and ∑DDT indicating potential environmental risk. This baseline data can be used as reference for regular ecological and future POPs monitoring program.
authors.affiliation: Department of Environmental Sciences, Hemwati Nandan Bahuguna Garhwal University (A Central University), Srinagar Garhwal-246174, Uttarakhand, India. saffron2882@gmail.com
authors.forename: Kumkum
authors.initials: K
authors.lastname: Mishra
authors.forename: Ramesh C
authors.initials: RC
authors.lastname: Sharma
authors.forename: Sudhir
authors.initials: S
authors.lastname: Kumar
mesh_terms: D003634:DDT / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D001556:Hexachlorocyclohexane / Q000032:analysis*; D007194:India; D060106:Lakes / Q000737:chemistry; D010575:Pesticides / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D001556:Hexachlorocyclohexane; D003634:DDT
keywords: DDT; HCH; India; Organochlorine pesticides; Surface sediments